Aiming at the problem of determining the development height of water flowing fractured zone after close-distance coal seam mining, 13 groups of experiments were designed by Box-Behnken method and the development height of water flowing fractured zone in each group of experiments was obtained by numerical simulation. The influence of the interaction of the three factors of cumulative coal thickness, working face length and advancing distance on the development height of water flowing fractured zone in close-distance coal seam was systematically analyzed. A quadratic response surface model with the development height of water flowing fractured zone as the response value was constructed, and the stope parameters of the optimal three factors were obtained. The variance analysis of the simulation results shows that the cumulative coal thickness is the biggest factor affecting the development height of the water-conducting fracture zone. The weight of the factors affecting the development height of the water-conducting fracture zone is ranked from large to small : cumulative mining thickness, working face length, and advancing distance. At the same time, the optimal parameters of the three factors are : when the cumulative coal thickness is 12m, the working face length of 180m is the optimal parameter ; when the cumulative coal thickness is 20m, the working face length of 180m is the optimal parameter. When the cumulative coal thickness is 28m, the working face length of 200m is the optimal parameter. It provides some reference and guidance for coal mining under similar geological conditions.